---
title: Retrievers
---

A [retriever](/oss/langchain/retrieval) is an interface that returns documents given an unstructured query.
It is more general than a vector store.
A retriever does not need to be able to store documents, only to return (or retrieve) them.

Retrievers accept a string query as input and return a list of Documents.

For specifics on how to use retrievers, see the [relevant how-to guides here](/oss/langchain/retrieval).

Note that all [vector stores](/oss/concepts/#vectorstores) can be [cast to retrievers](/oss/how-to/vectorstore_retriever/).
Refer to the vector store [integration docs](/oss/integrations/vectorstores/) for available vector store retrievers.

<Info>
If you'd like to write your own retriever, see [this how-to](/oss/how-to/custom_retriever/). If you'd like to contribute an integration, see [Contributing integrations](/oss/contributing#add-a-new-integration).
</Info>

## All retrievers

<Columns cols={3}>
  <Card
    title="ArxivRetriever"
    icon="link"
    href="/oss/integrations/retrievers/arxiv-retriever"
    arrow="true"
    cta="View guide"
  >
  </Card>
  <Card
    title="Azion EdgeSQL"
    icon="link"
    href="/oss/integrations/retrievers/azion-edgesql"
    arrow="true"
    cta="View guide"
  >
  </Card>
  <Card
    title="Knowledge Bases for Amazon Bedrock"
    icon="link"
    href="/oss/integrations/retrievers/bedrock-knowledge-bases"
    arrow="true"
    cta="View guide"
  >
  </Card>
  <Card
    title="BM25"
    icon="link"
    href="/oss/integrations/retrievers/bm25"
    arrow="true"
    cta="View guide"
  >
  </Card>
  <Card
    title="Chaindesk Retriever"
    icon="link"
    href="/oss/integrations/retrievers/chaindesk-retriever"
    arrow="true"
    cta="View guide"
  >
  </Card>
  <Card
    title="Dria Retriever"
    icon="link"
    href="/oss/integrations/retrievers/dria"
    arrow="true"
    cta="View guide"
  >
  </Card>
  <Card
    title="Exa"
    icon="link"
    href="/oss/integrations/retrievers/exa"
    arrow="true"
    cta="View guide"
  >
  </Card>
  <Card
    title="HyDE Retriever"
    icon="link"
    href="/oss/integrations/retrievers/hyde"
    arrow="true"
    cta="View guide"
  >
  </Card>
  <Card
    title="Amazon Kendra Retriever"
    icon="link"
    href="/oss/integrations/retrievers/kendra-retriever"
    arrow="true"
    cta="View guide"
  >
  </Card>
  <Card
    title="Metal Retriever"
    icon="link"
    href="/oss/integrations/retrievers/metal-retriever"
    arrow="true"
    cta="View guide"
  >
  </Card>
  <Card
    title="Self-querying retrievers"
    icon="link"
    href="/oss/integrations/retrievers/self_query"
    arrow="true"
    cta="View guide"
  >
  </Card>
  <Card
    title="Supabase Hybrid Search"
    icon="link"
    href="/oss/integrations/retrievers/supabase-hybrid"
    arrow="true"
    cta="View guide"
  >
  </Card>
  <Card
    title="Tavily Search API"
    icon="link"
    href="/oss/integrations/retrievers/tavily"
    arrow="true"
    cta="View guide"
  >
  </Card>
  <Card
    title="Time-Weighted Retriever"
    icon="link"
    href="/oss/integrations/retrievers/time-weighted-retriever"
    arrow="true"
    cta="View guide"
  >
  </Card>
  <Card
    title="Vespa Retriever"
    icon="link"
    href="/oss/integrations/retrievers/vespa-retriever"
    arrow="true"
    cta="View guide"
  >
  </Card>
  <Card
    title="Zep Cloud Retriever"
    icon="link"
    href="/oss/integrations/retrievers/zep-cloud-retriever"
    arrow="true"
    cta="View guide"
  >
  </Card>
  <Card
    title="Zep Open Source Retriever"
    icon="link"
    href="/oss/integrations/retrievers/zep-retriever"
    arrow="true"
    cta="View guide"
  >
  </Card>
</Columns>
